The invention relates generally to measuring apparatus and methods and in particular to a precision measuring apparatus and method for monitoring rotational and translational movement of one end of an deformable cylindrical member relative to the other end of the member.
Many measurement apparatus and methods can be employed for precisely measuring the relative position of the end of a generally cylindrical member. These methods and apparatus typically employ mechanical measurement techniques or invasive measurement apparatus and typically measure only a limited number of the degrees of freedom associated with the end of the member. For example, precision measurements are often made using electrical meters and gravity measurement devices, or can employ precisely aligned optical equipment.
One useful application for such measurement apparatus and methods can be, for example, in determining the direction of movement of tubing or drill elements in a slant oil well drilling operation. Another application can be to determine the precise initial conditions for a missile guidance system.
Accordingly, it is an object of the invention to provide high reliability precision measurement of one end of an cylindrical member relative to the other end thereof which is substantially stable and relatively insensitive to external environmental conditions, which is not an invasive form of measurement, and which can be employed in rugged and hostile environments.